British women may have paid too much for Anna Kournikova sports bras

Anna Kournikova at the 2000 launch of an ad campaign for the Shock Absorber sports bra. (Phil Cole/Getty/Allsport)

LONDON — It turns out British women may have paid too much for their underwear.

Britain's retail regulator said last week that it has evidence that an underwear maker and three department stores colluded to inflate the price of a popular sports bra once advertised by tennis star Anna Kournikova.

The U.K.'s Office of Fair Trading said it is investigating whether DB Apparel U.K. entered into anti-competitive agreements with retailers John Lewis, Debenhams and House of Fraser between 2008 and 2011 over the Shock Absorber bra. The regulator said its provisional view was that the manufacturer and the stores agreed on retail prices, in a "serious infringement of competition law."

The office's senior director of services, Ann Pope, said the agency would hear from the companies before making a final ruling.

The companies dispute the claims and say they are cooperating with investigators.

The Shock Absorber was once advertised by Kournikova under the slogan: "Only the balls should bounce."